FARMYARD MANURE. 33 



carbonaceous matter is destroyed, but little loss of 

 nitrogen takes place ; if , however, the manure gets dry 

 and mould appears, a serious loss of free nitrogen may 

 occur. Eotten manure, when well made, is more concen- 

 trated than the fresh, having greatly diminished in weight 

 during fermentation, with but little loss of valuable con- 

 stituents. Some of the constituents have also become 

 more soluble. Manure heaps in the open field should 

 be protected from waste by covering them with a layer 

 of earth 6 inches thick. 



Farmyard manure will contain from 65 to 80 per cent, 

 of water. The nitrogen maybe 0'40 to 0*65 per cent., or 

 higher, if produced by highly fed animals, or with peat 

 moss litter. The ash constituents will be 2*5 to 3 per 

 cent., exclusive of the sand and earth always present. 

 Of these ash constituents 0*4 to 0*7 will be potash; and 

 O2 to 0*4 phosphoric acid. One ton of farmyard manure 

 will thus supply 9 15 Ibs. of nitrogen, a similar 

 amount of potash, and 4 9 Ibs. of phosphoric acid. 



Farmyard manure is a " general" manure; that is, it 

 supplies all the essential elements of plant food. The 

 immediate return from an application of farmyard manure 

 is much less than from the same amount of plant food 

 applied in artificial manures. The effect of farmyard 

 manure is spread over a considerable number of years, its 

 nitrogen being chiefly present not as ammonia but in the 

 form of carbonaceous compounds, which decompose but 

 slowly in the soil. 



Farmyard manure improves the physical condition of 

 the soil, by increasing the proportion of humus present. 



Seaweed. This manure when fresh is, on the whole, 



